Just a comment from my experience...I completely agree with the notion that nest predators could be, and probably are, the #1 reason that turkey populations cannot bounce back once turk #'s are down in an area. To that point, I agree with all that has been said.
BUT...when our turkey population started diving 12'ish years ago we were commonly finding dead ADULT carcasses. In other words, coons and possums and other nest raiders weren't the culprit, as they could never catch enough healthy adult birds to impact the population to any degree.
What exactly killed those adults? I will never know for sure, but they were all consumed by the time we found them and some of them were partially buried, suggesting bobcat to me. Now then...did they die via whatever cause and then the next lucky meat eater that happened by found and enjoyed a free meal? I don't know...but I do know that these birds were fully adult and weren't killed as a poult or an egg.
I continue to be very, very interested in this topic, I would really like to be a part of a restoration...as the current population is really not even huntable IMO and I would like to take my grandson(s) turkey hunting some day, etc.
Nest raiders may be the #1 limiter, but there is more to this story than just a record number of coons in the timbers, at least IMO.